HP 6623A, 6624A, 6621A Unmask?, Unmask 2,XXX, Fault?, Bit Assignment of the Serial Poll Register

Page 75

The Mask and Fault Register. The fault register works in conjunction with the mask register. These are two eight bit registers which report any fault condition on a particular output channel. The mask register is used to set up the conditions that generate a fault which is latched into the fault register. The user can then read the fault register to determine the fault. When a bit in the fault register is set, the power supply can generate a service request for that output providing the service request command on fault (SRQ 1 or SRQ 3) was previously sent. See page 76 for a discussion on service request.

To understand how these two registers work, we must include the status register in this discussion. Recall that the status register takes its input from the power supply and the user cannot change its contents. The mask register takes its inputs from the user, and the power supply cannot change its contents. The fault register takes its inputs from both the mask and the status registers. You can find out the setting of the mask register of output 2 by sending the following query and addressing the supply to talk:

UNMASK? 2

The response will be a numeric code between 0 and 255 which can be decoded by consulting Table 5-5. You can set the conditions to generate a fault by setting (unmasking) one or more bits in the mask register. The conditions will remain unmasked until you change them. To unmask conditions in output 2 for example, send the following command:

UNMASK 2,XXX

where XXX specifies the numeric code (0 to 255) for the unmasked conditions (see Table 5-5). If during operation, the output experiences any of the previously unmasked conditions, it will set the corresponding bit(s) in its fault register.

Remember that the bits in the fault register can be set when there is a change in either the status register or the mask register. Each output has its status, mask, and fault registers arranged as shown in Figure 5-3 and Table 5-5. The mask register, which is set by the user, is used to specify which bits in the status register are enabled (unmasked) to set bits in the fault register. A bit is set in the fault register when the corresponding bit in the status register changes from "0'' to "1" and the corresponding bit in the mask register is a "1". Also, if a bit in the status register is already set and then the corresponding bit in the mask register is set (unmasked), the corresponding bit in the fault register will be set.

In addition, if both status and mask register bits remain set after the fault register was read (and cleared), the fault register will remain cleared as long as there are no changes in either the status or mask registers with the following exception. Executing a VSET, ISET, RCL, OVRST, OCRST, or OUT on/off command, will cause the CV, + CC, - CC, or UNR bit (as applicable) in the fault register to be set. Note that the fault register is cleared immediately after it is read.

As shown in Figure 5-3, if one or more bits in the fault register of a given output channel are set, then the FAU bit for that output in the serial poll register will also be set and a service request may be generated (see page 76). To read the fault register of output 2 and find out which bits are set, send the following query and address the supply to talk:

FAULT? 2

The power supply responds with a number which can be decoded from Table 5-5. For example, the number 9 (8 + 1) indicates that the OV and the CV bits in the fault register are set.

NOTE

If the condition(s) generating the fault(s) is (are) removed but the fault register is not read, the bit(s) in

 

the fault register will remain set.

The Serial Poll Register. The serial poll register is an 8 bit register which the supply uses to keep track of its internal operating status and to determine the operating status of each of its outputs. Table 5-6 defines each bit.

Table 5-6. Bit Assignment of the Serial Poll Register

Bit Position

7

6

5

4

3

2

1

0

Bit Weight

128

64

32

16

8

4

2

1

Meaning

PON

RQS

ERR

RDY

FAU 4

FAU 3

FAU 2

FAU 1

Remote Operation 75

Page 74 Page 76
Image 75
Page 74 Page 76
Contents HP Part No Operating ManualCertification Safety Summary Symbol Description Safety SummaryEMC Declaration of ConformityAppendix D--Error Messages Installation ProceduresAppendix A--Calibration Procedure Appendix C--Command SummaryTable Of Contents Local Operation Remote OperationProgramming With The Series 200/300 Computer Command SummaryError Messages CalibrationPage Instrument and Manual Identification Safety ConsiderationsGeneral Information IntroductionAccessories DescriptionOutput Combinations Available Model Basic Operation Output Low Range Values High Range ValuesHP-IB Board Output Boards Specifications Qualifying ConditionsDefinitions Output Response Characteristics Source Effect SpecificationsOutputs Low High Voltage Temperature Coefficient Supplemental CharacteristicsCommand Processing Time see Figure Outputs Low High Voltage Programming ResolutionReadback Resolution AC Input Power and CurrentLow Voltage High Voltage 80 W Low Voltage Safety Agency ComplianceDimensions all models Output ImpedanceGeneral Information General Information General Information General Information Installation Initial InspectionLocation and Cooling Line Fuse Input Power Requirements100/120 2110-0342 220/240 2110-0055 Line FusesLine Voltage Conversion Power CordHP-IB Interface Connector Page Front Panel Controls and Indicators Getting StartedTurning On Your Supply HP-IB Status Annunciators LCL keySystem Control Keys Power Supply StatusAnnunciators Alphanumeric LCDOutput Control Keys Line Switch Numeric Entry KeysNormal Self Test Indications Sample Self-Test Failure Display Checking Out Your Supply Using Local ControlVoltage Test Overvoltage TestCurrent Test Enter/Output Statements Introduction To Remote OperationIset Enter OCPAddr Sending a Remote CommandOutput Reading the HP-IB AddressOften Used Commands Getting Data From The SupplyDisp a Disp a Returning the Supply to Local Mode Output Ranges Output Connections and Operating InformationProtection Features Operating QuadrantsRange Selection Typical Output Range Characteristics Connecting the Load Page Wire Bundled 10 a 20 a FeetCross Section Meters Area in mm2 Remote Voltage Sensing Multiple LoadsPositive and Negative Voltages Remote Sense Connections Remote Voltage SensingOpen Sense Leads Output Type FormulaOutput Noise Considerations Programming Response Time with an Output CapacitorExternal Trigger Circuit Overvoltage Trigger ConnectionsEquivalent Internal OV Trigger Circuit Power Supply Protection Considerations Battery ChargingParallel Operation CV Operation Maximum Allowable Voltage SettingRemote Sensing CC Operation13. Series Connections with Local Sensing CV Operation Series Operation14. Series Connections with Remote Sensing Specifications for Series OperationPage Page Remote Operation HP-IB OperationInterface Function HP-IB Address Selection Power-On Service Request PON Programming SyntaxNumeric Data Sheet 1 of 2. Syntax Forms for Power Supply Commands Sheet 2 of 2. Syntax Forms for Power Supply Commands Ovset Fault ?Vset IsetPage Initial Conditions Power Supply CommandsCurrent Programming Voltage ProgrammingRange Switching Output On/Off Overvoltage OV ProtectionOVSET? Multiple Output Storage & Recall Overcurrent Protection OCPStatus Reporting Clear CommandASTS? UNR +CCBit Assignment of the Serial Poll Register FAULT?UNMASK? Unmask 2,XXXService Request Generation PON ? SRQ?Reprogramming Delay RQS BitDisplay On/Off Other Queries Front Panel ExplanationResponse Code Code Explanation TEST? ResponsesPage General Local ModeLocal Operation Local Control Of Output FunctionsSetting Current Setting VoltageDisplaying the Contents of the Fault Register Setting Overvoltage ProtectionResetting Overvoltage Protection Resetting Overcurrent ProtectionCondition Setting the Reprogramming DelaySetting the Supplys HP-IB Address Local Control Of System FunctionsRCL Enter Displaying Error MessagesAddr Enter STO EnterPage Test Equipment and Setup Required Calibration ProceduresFigure A-1. Calibration Setup General Calibration Procedure Are not stored. Exercise care when moving the leads Pause Calibration Program10 ! Calibration Example Clear Voltmeter Output BufferInput ANY More Outputs to CALIBRATE? Y or N,X$ Disp END of Calibration ProgramFnend Page Page Programming With a Series 200/300 Computer Path NamesVoltage and Current Programming Voltage and Current Readback Voltage and Current Programming With VariablesPresent Status Programming Power Supply RegistersPrint OUTPUT1 is in CV Mode END if Service Request and Serial PollPrint Overvoltage on Output #2 Enable IntrOFF Intr Print Overvoltage on Output #1Error Detection Stored Operating States Programming Outputs Connected In ParallelInput Enter Operating VOLTAGE,V1 Input Enter Voltage LIMIT,VInput Enter the Desired Current Limit POINT,I Programming Outputs Connected In SeriesCommand Summary Table C-1. Command SummaryCommand Description Table C-l. Command Summary ROM? PON?Previously Test Responses Error Codes and MessagesPower-On Self Test Messages Error Responses Table D-l. Power-On Self Test Error MessageError Code Message Explanation ERR? query ERR key Table D-2. Error ResponsesResponse Code Explanation TEST? query Table D-3. TEST? ResponsesPage Make Changes Manual Backdating6623A Generally Applicable AnnotationsII. CE92 Product Specific Annotations 6621ALatin America Or contactEurope Far East
Top Page Image Contents